Case of the Week
Section Editors: Matylda Machnowska1 and Anvita Pauranik2
1University of Toronto, Toronto, Ontario, Canada
2BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
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February 20, 2020
Olfactory Neuroblastoma
- Background:
- Also known as esthesioneuroblastoma, esthesioneuroepithelioma, or olfactory placode tumor
- These tumors arise from the olfactory neuroepithelium in the superior olfactory recess.
- They are unrelated to neuroblastoma elsewhere in the body.
- Clinical Presentation:
- Accounting for 2–6% of sinonasal tumors, these tumors occur most commonly in the 40–70-year age range.
- They are slow-growing, and patients usually present with gradually worsening nasal symptoms including stuffiness, rhinorrhea, and/or epistaxis.
- Due to their indolent growth, patients often present late with large, extensive tumors and may often have nodal disease.
- Key Diagnostic Features:
- Bone remodeling, rather than aggressive destruction, is common given the slow growth of these lesions and is best demonstrated on CT.
- MRI usually shows a T1-hypointense (to gray matter) and T2-intermediate-to-hyperintense lesion, but there may be some heterogeneity if there are areas of necrosis or hemorrhage. Generally, they show homogeneous avid enhancement.
- If there is intracranial extension, peripheral cysts are usually present at the brain interface, which is a useful discriminating feature from other lesions.
- Twenty percent of patients will develop metastases, usually to regional lymph nodes and most commonly cervical level II but also level I, III, or the retropharyngeal region.
- Approximately 5% of patients will have neck metastases at presentation. Other distant metastatic sites, although rare, include bone and CSF seeding.
- Differential Diagnoses:
- Olfactory groove meningioma: particularly if there is disproportionate intracranial involvement
- Sinonasal carcinoma: usually older patients, no peritumoral cysts, more aggressive bone destruction and shorter history
- Nasopharyngeal carcinoma: usually more posteriorly located, more aggressive bone destruction and shorter history
- Juvenile angiofibroma: usually younger adults and more posteriorly located
- Treatment:
- Surgical craniofacial resection with neoadjuvant chemotherapy and/or adjuvant radiotherapy
- Five-year survival is approximately 64% for those without versus 29% with nodal disease at presentation